In Power-over-Ethernet (PoE) systems in accordance with the PoE standard IEEE 802.3at, a power sourcing device (power sourcing equipment; PSE) sources a power to one or several powered devices (PD) via one or several Ethernet cables. The power sourcing device is, e.g., a switch and the powered devices are, e.g., security cameras, wireless access points, VoIP telephones, etc. In accordance with the standard, the power consumption of the powered devices is limited to only a comparably small power level, which is smaller than the power level sourcable by each port of the power sourcing device, in order to compensate for possible losses in the Ethernet cables.
US 2006/0164769 A1 discloses a system and methodology for adjusting a current limit threshold in a PoE system in accordance with requirements of a PD. A system for supplying power to a PD over a communications link has a requirement determining circuit for determining a PD's requirement, and a control circuit for setting a parameter restricting an output signal of the PSE in accordance with the determined PD's requirement. The control circuit may set a current limit threshold of the PSE and/or the PD in accordance with the determined PD's requirement, such as a power requirement.